export default function() {
  // var devicePixelRatio = 1;
  // var scale = 1 / devicePixelRatio;
  // document.querySelector('meta[name="viewport"]').setAttribute('content','initial-scale=' + scale + ', maximum-scale=' + scale + ', minimum-scale=' + scale + ', user-scalable=no');
  // 7.5根据设计稿的横向分辨率/100得来
  // alert(document.documentElement.clientWidth)
  var deviceWidth = document.documentElement.clientWidth;
  // var deviceWidth = window.screen.availWidth
  // alert(navigator.userAgent)
  // alert(deviceWidth)
  // console.log(navigator.userAgent)
  if (deviceWidth > 750) {
    // deviceWidth = 750;
    deviceWidth = 7.5 * 50;
  }

  document.documentElement.style.fontSize = deviceWidth / 7.5 + "px";

  // 禁止双击放大
  document.documentElement.addEventListener(
    "touchstart",
    function(event) {
      if (event.touches.length > 1) {
        event.preventDefault();
      }
    },
    false
  );
  var lastTouchEnd = 0;
  document.documentElement.addEventListener(
    "touchend",
    function(event) {
      var now = Date.now();
      if (now - lastTouchEnd <= 300) {
        event.preventDefault();
      }
      lastTouchEnd = now;
    },
    false
  );
}
